Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
827
FXUS66 KSEW 210317
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
817 PM PDT Sat Apr 20 2019

.SYNOPSIS...After areas of morning low clouds, there will be
more sunshine on Sunday. A front will reach the area Monday
afternoon and evening, then stall over Western Washington as it
weakens on Tuesday. Another front will arrive late in the week.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...Skies are mostly clear this
evening. Areas of low clouds will develop overnight, linger Sunday
morning, and then burn off by midday. Areas from the Puget Sound
basin south though Olympia and Chehalis are more likely to have
morning clouds than the coast and north. On Monday a frontal system
will reach the area: The 18z GFS has some rain on the coast in
the morning--but not much rain up and down the I-5 corridor til
evening. The front looks like it could still be hung up over the
area on Tuesday--with some rain or showers more likely along the
west slopes of the Cascades and in the convergence zone.

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...Conditions may quickly
dry up Tuesday night into Wednesday as ridging briefly returns to
the area for Wednesday into Thursday. Dry weather should rule with
temperatures a degree or two warmer. Model solutions differ past
Thursday with ECWMF hanging onto the ridge for another day and the
GFS showing the next system moving across the area with showers
into the weekend. Have low chances of precipitation in current
forecast until solutions become more consistent. CEO

&&

.AVIATION...Mostly clear skies this evening will give way to areas
of low clouds later today--mainly for the Seattle area south. The
morning clouds will probably be patchier from Everett north.

KSEA...Morning low clouds are a good bet Sunday and a light
southwest breeze should persist through the day.

&&

.MARINE...Onshore flow will continue this weekend with high
pressure over the NE Pacific. Highest wind and waves will be over
the Coastal Waters and through the Strait of Juan de Fuca - Small
Craft Advisories are in effect. A frontal system will reach the
area Monday then weaken and move inland Monday night and Tuesday.
Low level onshore flow will prevail behind this system on
Wednesday.

&&

.HYDROLOGY...River flooding is not expected across the area for
the next 7 days.


&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 11 PM PDT this evening for Coastal
     Waters From Cape Flattery To James Island 10 To 60 Nm-
     Coastal Waters From Cape Flattery To James Island Out 10 Nm-
     Coastal Waters From James Island To Point Grenville 10 To
     60 Nm-Coastal Waters From James Island To Point Grenville
     Out 10 Nm-Coastal Waters From Point Grenville To Cape
     Shoalwater 10 To 60 Nm-Coastal Waters From Point Grenville
     To Cape Shoalwater Out 10 Nm.

     Small Craft Advisory until 8 AM PDT Sunday for Central U.S.
     Waters Strait Of Juan De Fuca-East Entrance U.S. Waters
     Strait Of Juan De Fuca.&&

$$

www.weather.gov/seattle



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.